Mud flaps or analogous systems are required by certain trucks to minimize the potential for debris to be kicked up by truck wheels, possibly causing damage to other vehicles. Such mud flaps are typically in the form of planar flexible heavy rubber structures suspended in a vertical plane from upper ends thereof coupled to a bumper or other suspension arm behind wheels of the vehicle. Such suspension is typically rigid in form.
For mud flaps to function optimally, they should be as close to the roadway as possible. However, low positioning of the mud flaps can be problematic. For instance, when a truck is backing up, it is often desirable to back up until rear wheels of the vehicle bump against a curb or other obstruction. If the mud flaps are in an optimal low position, lower edges of the mud flaps will be pinched between the wheels of the vehicle and the curb. Even the slightest additional movement of the truck causes very high downward tension loads on the mud flap, often causing the mud flap to tear, or bending of rigid support arms holding the mud flaps. Such downward loads associated with pinching of the mud flaps can be translational only in a downward direction, or can be both downward and rotational, particularly if only one corner of the mud flap becomes trapped. Translational loads and rotational loads have a different affect on the mud flap.
One prior art mud flap suspension system usable primarily only on trucks having a central frame involves a cantilevered housing extending perpendicularly from the central frame directly behind the wheels of the vehicle. This cantilevered support housing is known in at least some systems to be attached through a heavy spring which facilitates a small amount of pivoting of the cantilevered support housing relative to the central frame of the truck. The mud flaps are rigidly mounted to the cantilevered support housing.
Such systems are not entirely desirable in that only a small amount of mud flap downward travel is facilitated, and the pivoting of the cantilevered arm is only optimal in a small number of mud flap pinching scenarios. For instance, mud flaps can be pinched and pulled downward in a translating motion, can be pinched and rotated toward a center of the truck, or pinched and rotated away from a center of the truck. Prior art spring mounted cantilevered housing mud flap suspension systems only best accommodate a pinching and rotating toward a centerline of the truck motion; with the mud flaps returning to their original position when pinching loads subside. Accordingly, a need exists for a resilient mud flap suspension system that can accommodate a large amount of mud flap travel with both translation and/or rotation.